Electromagnetic correlation imaging: image quality and the degree of polarisation

Image quality of various correlation imaging setups is investigated while taking into account the electromagnetic nature of light, especially the degree of polarisation. Classical ghost imaging with vectorial light, or electromagnetic correlation imaging, is a 21st century imaging method that can be applied to situations where conventional, direct imaging methods are not possible. This novel imaging method is based on the statistical nature of the light source which is followed by an inherent image quality disadvantage compared to conventional imaging methods. The degree of polarization of the source has an effect on the image quality, as does the exact arrangement of the setup. Various configurations with two, three or more paths that light originating from a common source takes before it is detected and the image is formed through correlation calculations are explored. Powerful methods for analysing various setups are presented, such as the concept of the fictitious plane of the effective source, and both analytical and computational methods for efficiently calculating higher-order correlations. It is found that while increasing the degree of polarisation of the source or the number of paths taken enhances the image quality when measured by certain parameters, it decreases the image quality when assessing the result using other image quality parameters. The results of this work can be used to analyse more specific studies and to help improve their image quality.